Atmospheric turbulence is a problem that is commonly encountered by aircraft. Atmospheric turbulence typically refers to localized wind variations, i.e., rapid differences in wind speed and/or direction from an average or a mean flow of air. For example, atmospheric turbulence may include but is not limited to, wind shear, wind gradients, clear-air turbulence, wake turbulence, “air pockets”, and the like. Furthermore, atmospheric turbulence may be broken down into two components, vertical and horizontal wind shears or gusts of wind. Vertical shear or gusts of wind typically occur at higher levels in the atmosphere and above or near a vertical surface, such as a mountain. Horizontal shear may occur near weather fronts or near a coastal region. For example, aircraft pilots may consider a vertical speed change that is greater than 152 meters/500 feet per minute or a horizontal change in airspeed of 30 knots/15 m/s to be significant wind shear. Thus, pilots try to avoid flying in turbulent conditions, such as the significant wind shear conditions as described, whenever possible.
There may be different factors causing atmospheric turbulence. In some cases, the turbulence may be caused by erratic movement of air masses in the absence of any clouds; mixture of warm and cold air in the atmosphere, movement of winds in different directions or near the edges or intersections of a jetstream. Turbulence may also occur in the vicinity of, but outside of thunderstorms. Along with these factors, atmospheric turbulence is typically difficult to detect with the naked eye or with conventional radar (unless moisture is present). As a result, turbulence may create hazards for air navigation.
Due to the difficulties in detecting and avoiding turbulence, there may be times when the pilots are flying the aircraft into turbulent conditions without notice. If this situation occurs, the turbulent conditions may cause motion sickness and/or anxiety for passengers and flight crew, and may reduce ride quality and/or comfort for passengers. Therefore, it is desirable to find ways to keep the aircraft flight as smooth as possible.